//-----------------------------------------------------------------------------
// Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// Data and Graph commands
//-----------------------------------------------------------------------------

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include "proxmark3.h"
#include "data.h"
#include "ui.h"
#include "graph.h"
#include "cmdparser.h"
#include "util.h"
#include "cmdmain.h"
#include "cmddata.h"
#include "lfdemod.h"

static int CmdHelp(const char *Cmd);

int CmdAmp(const char *Cmd)
{
	int i, rising, falling;
	int max = INT_MIN, min = INT_MAX;

	DetectHighLowInGraph( &max, &min, FALSE);

	if (max != min) {
		rising = falling = 0;
		
		for (i = 0; i < GraphTraceLen; ++i) {
			if (GraphBuffer[i + 1] < GraphBuffer[i]) {
				if (rising) {
					GraphBuffer[i] = max;
					rising = 0;
				}
				falling = 1;
			}
			if (GraphBuffer[i + 1] > GraphBuffer[i]) {
				if (falling) {
					GraphBuffer[i] = min;
					falling = 0;
				}
				rising= 1;
			}
		}
	}
	RepaintGraphWindow();
	return 0;
}

/*
 * Generic command to demodulate ASK.
 *
 * Argument is convention: positive or negative (High mod means zero
 * or high mod means one)
 *
 * Updates the Graph trace with 0/1 values
 *
 * Arguments:
 * c : 0 or 1
 */
 //this method is dependant on all highs and lows to be the same(or clipped)  this creates issues[marshmellow] it also ignores the clock
int Cmdaskdemod(const char *Cmd)
{
	int i;
	int c, high = 0, low = 0;

	sscanf(Cmd, "%i", &c);

	if (c != 0 && c != 1) {
		PrintAndLog("Invalid argument: %s", Cmd);
		return 0;
	}

	DetectHighLowInGraph( &high, &low, FALSE);

	high = abs(high * .75);
	low = abs(low * .75);

	//prime loop
	if (GraphBuffer[0] > 0) {
		GraphBuffer[0] = 1-c;
	} else {
		GraphBuffer[0] = c;
	}
	
	for (i = 1; i < GraphTraceLen; ++i) {
		/* Transitions are detected at each peak
		 * Transitions are either:
		 * - we're low: transition if we hit a high
		 * - we're high: transition if we hit a low
		 * (we need to do it this way because some tags keep high or
		 * low for long periods, others just reach the peak and go
		 * down)
		 */
		if ((GraphBuffer[i] == high) && (GraphBuffer[i - 1] == c)) {
		  GraphBuffer[i] = 1 - c;
		} else if ((GraphBuffer[i] == low) && (GraphBuffer[i - 1] == (1 - c))){
		  GraphBuffer[i] = c;
		} else {
		  /* No transition */
		  GraphBuffer[i] = GraphBuffer[i - 1];
		}
	}
  RepaintGraphWindow();
  return 0;
}

void printBitStream(uint8_t bits[], uint32_t bitLen){

	uint32_t i = 0;
	if (bitLen < 16) {
		PrintAndLog("Too few bits found: %d",bitLen);
		return;
	}
	if (bitLen > 512) 
		bitLen = 512;
		
	if ( ( bitLen % 16 ) > 0) {
		bitLen = ((bitLen / 16) * 16);
		PrintAndLog("ICE: equally divided with 16 = %d",bitLen);
	}
	
	for (i = 0; i <= ( bitLen - 16); i += 16) {
		PrintAndLog("%i%i%i%i%i%i%i%i%i%i%i%i%i%i%i%i",
			bits[i],
			bits[i+1],
			bits[i+2],
			bits[i+3],
			bits[i+4],
			bits[i+5],
			bits[i+6],
			bits[i+7],
			bits[i+8],
			bits[i+9],
			bits[i+10],
			bits[i+11],
			bits[i+12],
			bits[i+13],
			bits[i+14],
			bits[i+15]);
	}
  return; 
}

void printEM410x(uint64_t id) {

	if ( id <= 0 ) return;
	
	uint64_t id2lo = 0; 
	uint32_t i,j;
	i = j = 0;
	
	for (j = 5; j > 0; j--){
		for (i = 0; i < 8; i++){
			id2lo = ( id2lo << 1LL)|((id & ( 1 << ( i +( ( j-1 ) * 8 )))) >> ( i + (( j-1) *8 )));
		}
	}
	//output em id
	PrintAndLog("EM TAG ID    : %010llx", id);
	PrintAndLog("Unique TAG ID: %010llx", id2lo);
	PrintAndLog("DEZ 8        : %08lld", id & 0xFFFFFF);
	PrintAndLog("DEZ 10       : %010lld", id & 0xFFFFFF);
	PrintAndLog("DEZ 5.5      : %05lld.%05lld", (id>>16LL) & 0xFFFF, (id & 0xFFFF));
	PrintAndLog("DEZ 3.5A     : %03lld.%05lld", (id>>32ll), (id & 0xFFFF));
	PrintAndLog("DEZ 14/IK2   : %014lld", id);
	PrintAndLog("DEZ 15/IK3   : %015lld", id2lo);
	PrintAndLog("Other        : %05lld_%03lld_%08lld", (id & 0xFFFF), (( id >> 16LL) & 0xFF), (id & 0xFFFFFF));
}

int CmdEm410xDecode(const char *Cmd)
{
	uint64_t id = 0;
	uint8_t bits[MAX_GRAPH_TRACE_LEN] = {0x00};
	uint32_t len = GetFromGraphBuf(bits);
	id = Em410xDecode(bits, len);
	printEM410x(id);
	if ( id > 0 ) 
		return 1;
	return 0;
}

//by marshmellow
//takes 2 arguments - clock and invert both as integers 
//attempts to demodulate ask while decoding manchester 
//prints binary found and saves in graphbuffer for further commands
int Cmdaskmandemod(const char *Cmd)
{
	int invert = 0; 
	int clk = 0; 

	sscanf(Cmd, "%i %i", &clk, &invert);    

	if (invert != 0 && invert != 1) {
		PrintAndLog("Invalid argument: %s", Cmd);
		return 0;
	}
  
	uint8_t bits[MAX_GRAPH_TRACE_LEN] = {0x00};
	uint32_t len = GetFromGraphBuf(bits);

	int errCnt = askmandemod(bits, &len, &clk, &invert);

	if (errCnt < 0) return 0;
	if (len < 16) return 0;
  
	PrintAndLog("\nUsing Clock: %d - Invert: %d - Bits Found: %d",clk,invert,len);

	if (errCnt > 0){
		PrintAndLog("# Errors during Demoding (shown as 77 in bit stream): %d",errCnt);
	}
  
	PrintAndLog("ASK/Manchester decoded bitstream:");

	printBitStream(bits, len);

	uint64_t tagid = Em410xDecode(bits, len);

	if (tagid > 0){
		SetGraphBuf(bits, len); 
		printEM410x(tagid);
		return 1;
	}
	return 0;
}

//by marshmellow
//manchester decode
//stricktly take 10 and 01 and convert to 0 and 1
int Cmdmandecoderaw(const char *Cmd)
{
	int i = 0;
	int errCnt = 0;
	int bitnum = 0;
	uint8_t bits[MAX_GRAPH_TRACE_LEN] = {0x00};
	int high = 0, low = 0;

	for (; i < GraphTraceLen; ++i){
		if (GraphBuffer[i] > high) high = GraphBuffer[i];
		else if (GraphBuffer[i] < low) low = GraphBuffer[i];
		bits[i] = GraphBuffer[i];
	}
	
	if (high > 1 || low < 0 ){
		PrintAndLog("Error: please raw demod the wave first then mancheseter raw decode");
		return 0;
	}

	bitnum = i;
	errCnt = manrawdecode(bits, &bitnum);

	if (errCnt>=20){
		PrintAndLog("Too many errors: %d",errCnt);
		return 0;
	}
	
	PrintAndLog("Manchester Decoded - # errors:%d - data:",errCnt);
	printBitStream(bits,bitnum);

	if (errCnt==0){
	//put back in graphbuffer
	SetGraphBuf(bits, bitnum);

	uint64_t id = Em410xDecode(bits,i);
	printEM410x(id);     
	}
	return 1;
}

//by marshmellow
//biphase decode
//take 01 or 10 = 0 and 11 or 00 = 1
//takes 1 argument "offset" default = 0 if 1 it will shift the decode by one bit
//  since it is not like manchester and doesn't have an incorrect bit pattern we 
//  cannot determine if our decode is correct or if it should be shifted by one bit
//  the argument offset allows us to manually shift if the output is incorrect
//  (better would be to demod and decode at the same time so we can distinguish large
//    width waves vs small width waves to help the decode positioning) or askbiphdemod
int CmdBiphaseDecodeRaw(const char *Cmd)
{
	int i = 0;
	int errCnt = 0;
	int bitnum = 0;
	int offset = 0;
	int high = 0, low = 0;
	sscanf(Cmd, "%i", &offset);    

	uint8_t bits[MAX_GRAPH_TRACE_LEN]={0};

	//get graphbuffer & high and low
	for (; i<GraphTraceLen; ++i){
		if (GraphBuffer[i] > high) high = GraphBuffer[i];
		else if (GraphBuffer[i] < low) low = GraphBuffer[i];
		bits[i] = GraphBuffer[i];
	}
	if (high > 1 || low < 0){
		PrintAndLog("Error: please raw demod the wave first then decode");
		return 0;
	}
	bitnum = i;
	errCnt = BiphaseRawDecode(bits, &bitnum, offset);
	if (errCnt >= 20){
		PrintAndLog("Too many errors attempting to decode: %d", errCnt);
		return 0;
	}
	PrintAndLog("Biphase Decoded using offset: %d - # errors:%d - data:", offset, errCnt);
	printBitStream(bits, bitnum);
	PrintAndLog("\nif bitstream does not look right try offset=1");
	return 1;
}


//by marshmellow
//takes 2 arguments - clock and invert both as integers
//attempts to demodulate ask only
//prints binary found and saves in graphbuffer for further commands
int Cmdaskrawdemod(const char *Cmd)
{
	int invert = 0; 
	int clk = 0; 

	sscanf(Cmd, "%i %i", &clk, &invert);

	if (invert != 0 && invert != 1 ) {
		PrintAndLog("Invalid argument: %s", Cmd);
		return 0;
	}
	
	if ( clock < 0 ) {
		PrintAndLog("Wrong clock argument");
		return 0;
	}

	uint8_t bits[MAX_GRAPH_TRACE_LEN] = {0x00};
	int len = GetFromGraphBuf(bits);
	int errCnt = 0;

	errCnt = askrawdemod(bits, &len, &clk, &invert);
	
	//throw away static - allow 1 and -1 (in case of threshold command first)
	if (errCnt == -1) {  
		PrintAndLog("no data found"); 
		return 0;
	} 

	if (len < 16) return 0;
	
	PrintAndLog("Using Clock: %d - invert: %d - Bits Found: %d",clk,invert,len);

	//move BitStream back to GraphBuffer
	SetGraphBuf(bits, len);
	
	if (errCnt > 0){
	  PrintAndLog("# Errors during Demoding (shown as 77 in bit stream): %d",errCnt);
	}

	PrintAndLog("ASK demoded bitstream:");
	
	// Now output the bitstream to the scrollback by line of 16 bits
	printBitStream(bits,len);
	return 1;
}

int CmdAutoCorr(const char *Cmd)
{
  static int CorrelBuffer[MAX_GRAPH_TRACE_LEN];

  int window = atoi(Cmd);

  if (window == 0) {
    PrintAndLog("needs a window");
    return 0;
  }
  if (window >= GraphTraceLen) {
    PrintAndLog("window must be smaller than trace (%d samples)",
      GraphTraceLen);
    return 0;
  }

  PrintAndLog("performing %d correlations", GraphTraceLen - window);

  for (int i = 0; i < GraphTraceLen - window; ++i) {
    int sum = 0;
    for (int j = 0; j < window; ++j) {
      sum += (GraphBuffer[j]*GraphBuffer[i + j]) / 256;
    }
    CorrelBuffer[i] = sum;
  }
  GraphTraceLen = GraphTraceLen - window;
  memcpy(GraphBuffer, CorrelBuffer, GraphTraceLen * sizeof (int));

  RepaintGraphWindow();
  return 0;
}

int CmdBitsamples(const char *Cmd)
{
  int cnt = 0;
  uint8_t got[10000];
  
  GetFromBigBuf(got,sizeof(got),0);
  WaitForResponse(CMD_ACK,NULL);

    for (int j = 0; j < sizeof(got); j++) {
      for (int k = 0; k < 8; k++) {
        if(got[j] & (1 << (7 - k))) {
          GraphBuffer[cnt++] = 1;
        } else {
          GraphBuffer[cnt++] = 0;
        }
      }
  }
  GraphTraceLen = cnt;
  RepaintGraphWindow();
  return 0;
}

/*
 * Convert to a bitstream
 */
int CmdBitstream(const char *Cmd)
{
  int i, j;
  int bit;
  int gtl;
  int clock;
  int low = 0;
  int high = 0;
  int hithigh, hitlow, first;

  /* Detect high and lows and clock */
  DetectHighLowInGraph( &high, &low, FALSE); 

  /* Get our clock */
  clock = GetClock(Cmd, 0);
  gtl = ClearGraph(0);

  bit = 0;
  for (i = 0; i < (int)(gtl / clock); ++i)
  {
    hithigh = 0;
    hitlow = 0;
    first = 1;
    /* Find out if we hit both high and low peaks */
    for (j = 0; j < clock; ++j)
    {
      if (GraphBuffer[(i * clock) + j] == high)
        hithigh = 1;
      else if (GraphBuffer[(i * clock) + j] == low)
        hitlow = 1;
      /* it doesn't count if it's the first part of our read
         because it's really just trailing from the last sequence */
      if (first && (hithigh || hitlow))
        hithigh = hitlow = 0;
      else
        first = 0;

      if (hithigh && hitlow)
        break;
    }

    /* If we didn't hit both high and low peaks, we had a bit transition */
    if (!hithigh || !hitlow)
      bit ^= 1;

    AppendGraph(0, clock, bit);
  }

  RepaintGraphWindow();
  return 0;
}

int CmdBuffClear(const char *Cmd)
{
  UsbCommand c = {CMD_BUFF_CLEAR};
  SendCommand(&c);
  ClearGraph(true);
  return 0;
}

int CmdDec(const char *Cmd)
{
  for (int i = 0; i < (GraphTraceLen / 2); ++i)
    GraphBuffer[i] = GraphBuffer[i * 2];
  GraphTraceLen /= 2;
  PrintAndLog("decimated by 2");
  RepaintGraphWindow();
  return 0;
}

/* Print our clock rate */
// uses data from graphbuffer 
int CmdDetectClockRate(const char *Cmd)
{
  GetClock("",1);
  return 0;
}

//by marshmellow
//fsk raw demod and print binary
//takes 4 arguments - Clock, invert, rchigh, rclow
//defaults: clock = 50, invert=0, rchigh=10, rclow=8 (RF/10 RF/8 (fsk2a))
int CmdFSKrawdemod(const char *Cmd)
{
	//raw fsk demod no manchester decoding no start bit finding just get binary from wave
	int rfLen = 50;
	int invert = 0;
	int fchigh = 10;
	int fclow = 8;

	//set options from parameters entered with the command
	sscanf(Cmd, "%i %i %i %i", &rfLen, &invert, &fchigh, &fclow);    
  
	// A lots of checks if chigh, clow is out-of bounds.
  
	if (strlen(Cmd)>0 && strlen(Cmd)<=2) {
		
		rfLen = 50;
		
		//if invert option only is used
		if (rfLen == 1){
			invert=1;   
		}
	} 
	
	PrintAndLog("Args invert: %d - Clock:%d - FC high:%d - FC low: %d",invert,rfLen,fchigh, fclow);

	uint8_t bits[MAX_GRAPH_TRACE_LEN] = {0x00};
	uint32_t len = GetFromGraphBuf(bits);

	int size  = fskdemod(bits, len,(uint8_t)rfLen, (uint8_t)invert, (uint8_t)fchigh, (uint8_t)fclow); 

	if (size > 0) {
		PrintAndLog("FSK decoded bitstream:");
		
		SetGraphBuf(bits, size);
  
		// Now output the bitstream to the scrollback by line of 16 bits
		// only output a max of 8 blocks of 32 bits  most tags will have full bit stream inside that sample size
		if(size > (8*32)+2)
			size = (8*32)+2; 
		printBitStream(bits,size);
	} else {
		PrintAndLog("no FSK data found");
	}
	return 0;
}

//by marshmellow (based on existing demod + holiman's refactor)
//HID Prox demod - FSK RF/50 with preamble of 00011101 (then manchester encoded)
//print full HID Prox ID and some bit format details if found
int CmdFSKdemodHID(const char *Cmd)
{
	//raw fsk demod no manchester decoding no start bit finding just get binary from wave
	uint32_t hi2=0, hi=0, lo=0;

	uint8_t BitStream[MAX_GRAPH_TRACE_LEN] = {0x00};
	uint32_t BitLen = GetFromGraphBuf(BitStream);

	//get binary from fsk wave
	size_t size  = HIDdemodFSK(BitStream,BitLen,&hi2,&hi,&lo); 

	if (size < 0){
		PrintAndLog("Error demoding fsk");
		return 0;
	}
	
	if (hi2==0 && hi==0 && lo==0) return 0;

	//extra large HID tags	
	if (hi2 != 0){
		PrintAndLog("TAG ID: %x%08x%08x (%d)",
						(unsigned int) hi2,
						(unsigned int) hi,
						(unsigned int) lo,
						(unsigned int) (lo>>1) & 0xFFFF);
		SetGraphBuf(BitStream,BitLen);
		return 1;
	} else {  
		//standard HID tags <38 bits
		uint8_t fmtLen = 0;
		uint32_t fc = 0;
		uint32_t cardnum = 0;
		
		//if bit 38 is set then < 37 bit format is used
		if (((hi>>5) & 1)==1){
			uint32_t lo2 = 0;
			
			 //get bits 21-37 to check for format len bit
			lo2 = (((hi & 15) << 12) | (lo>>20));
			uint8_t idx3 = 1;

			//find last bit set to 1 (format len bit)
			while( lo2 > 1){ 
				lo2=lo2>>1;
				idx3++;
			}
			fmtLen = idx3 + 19;  
			fc = 0;
			cardnum = 0;
			
			if(fmtLen==26){
				cardnum = (lo>>1)&0xFFFF;
				fc = (lo>>17)&0xFF;
			}
			if(fmtLen==37){
                cardnum = (lo>>1)&0x7FFFF;
                fc = ((hi&0xF)<<12)|(lo>>20);
              }
			if(fmtLen==34){
                cardnum = (lo>>1)&0xFFFF;
                fc= ((hi&1)<<15)|(lo>>17);
			}
			if(fmtLen==35){
                cardnum = (lo>>1)&0xFFFFF;
                fc = ((hi&1)<<11)|(lo>>21);
			}
		} else { 
			//if bit 38 is not set then 37 bit format is used
			fmtLen= 37;
			fc =0;
			cardnum=0;
			
			if (fmtLen==37){
                cardnum = (lo>>1) & 0x7FFFF;
                fc = ((hi&0xF) << 12) | (lo >> 20);
              }
		}
		PrintAndLog("TAG ID: %x%08x (%d) - Format Len: %dbit - FC: %d - Card: %d",
						(unsigned int) hi,
						(unsigned int) lo,
						(unsigned int) (lo>>1) & 0xFFFF,
						(unsigned int) fmtLen, 
						(unsigned int) fc, 
						(unsigned int) cardnum);
    SetGraphBuf(BitStream,BitLen);
    return 1;
          }
  return 0;
}

//by marshmellow
//IO-Prox demod - FSK RF/64 with preamble of 000000001
//print ioprox ID and some format details
int CmdFSKdemodIO(const char *Cmd)
{
	if (GraphTraceLen < 65) {
		PrintAndLog("data samples size is too small");
		return 0;
	}

	//raw fsk demod no manchester decoding no start bit finding just get binary from wave
	//set defaults
	int idx = 0; 
	uint8_t bits[MAX_GRAPH_TRACE_LEN] = {0x00};
	uint32_t bitlen = GetFromGraphBuf(bits);

	//get binary from fsk wave
	idx = IOdemodFSK(bits, bitlen); 
  
	if (idx == 0) {
		return 0;
	}
	if (idx == -1) {
		PrintAndLog("data samples size is too small");
		return 0;
	}
	if (idx == -2) {
		PrintAndLog("Data samples has too much noice");
		return 0;
	}
	if (idx == -3){
		PrintAndLog("No good demod");
		return 0;
	}
  
	if (idx+64 > bitlen) return 0;
  
	//Index map
	//0           10          20          30          40          50          60
	//|           |           |           |           |           |           |
	//01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
	//-----------------------------------------------------------------------------
	//00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
	//
	//XSF(version)facility:codeone+codetwo (raw)
	//Handle the data

	PrintAndLog("%d%d%d%d%d%d%d%d %d",			bits[idx]   , bits[idx+1],  bits[idx+2], bits[idx+3], bits[idx+4], bits[idx+5], bits[idx+6], bits[idx+7], bits[idx+8]);
	PrintAndLog("%d%d%d%d%d%d%d%d %d",			bits[idx+9] , bits[idx+10], bits[idx+11], bits[idx+12], bits[idx+13], bits[idx+14], bits[idx+15], bits[idx+16], bits[idx+17]);       
	PrintAndLog("%d%d%d%d%d%d%d%d %d facility", bits[idx+18], bits[idx+19], bits[idx+20], bits[idx+21], bits[idx+22], bits[idx+23], bits[idx+24], bits[idx+25], bits[idx+26]);
	PrintAndLog("%d%d%d%d%d%d%d%d %d version",	bits[idx+27], bits[idx+28], bits[idx+29], bits[idx+30], bits[idx+31], bits[idx+32], bits[idx+33], bits[idx+34], bits[idx+35]);
	PrintAndLog("%d%d%d%d%d%d%d%d %d code1",	bits[idx+36], bits[idx+37], bits[idx+38], bits[idx+39], bits[idx+40], bits[idx+41], bits[idx+42], bits[idx+43], bits[idx+44]);
	PrintAndLog("%d%d%d%d%d%d%d%d %d code2",	bits[idx+45], bits[idx+46], bits[idx+47], bits[idx+48], bits[idx+49], bits[idx+50], bits[idx+51], bits[idx+52], bits[idx+53]);
	PrintAndLog("%d%d%d%d%d%d%d%d %d%d checksum", bits[idx+54], bits[idx+55], bits[idx+56], bits[idx+57], bits[idx+58], bits[idx+59], bits[idx+60], bits[idx+61], bits[idx+62], bits[idx+63]);

	uint32_t code = bytebits_to_byte(bits+idx,32);
	uint32_t code2 = bytebits_to_byte(bits+idx+32,32); 
	uint8_t version = bytebits_to_byte(bits+idx+27,8); //14,4
	uint8_t facilitycode = bytebits_to_byte(bits+idx+18,8) ;
	uint16_t number = (bytebits_to_byte(bits+idx+36,8)<<8)|(bytebits_to_byte(bits+idx+45,8)); //36,9
		  
	PrintAndLog("XSF(%02d)%02x:%05d (%08x%08x)", version, facilitycode, number, code, code2);    
	SetGraphBuf(bits, bitlen);
	return 1;
}

int CmdFSKdemod(const char *Cmd) //old CmdFSKdemod needs updating
{
  static const int LowTone[]  = {
    1,  1,  1,  1,  1, -1, -1, -1, -1, -1,
    1,  1,  1,  1,  1, -1, -1, -1, -1, -1,
    1,  1,  1,  1,  1, -1, -1, -1, -1, -1,
    1,  1,  1,  1,  1, -1, -1, -1, -1, -1,
    1,  1,  1,  1,  1, -1, -1, -1, -1, -1
  };
  static const int HighTone[] = {
    1,  1,  1,  1,  1,     -1, -1, -1, -1,
    1,  1,  1,  1,         -1, -1, -1, -1,
    1,  1,  1,  1,         -1, -1, -1, -1,
    1,  1,  1,  1,         -1, -1, -1, -1,
    1,  1,  1,  1,         -1, -1, -1, -1,
    1,  1,  1,  1,     -1, -1, -1, -1, -1,
  };

  int lowLen = sizeof (LowTone) / sizeof (int);
  int highLen = sizeof (HighTone) / sizeof (int);
  int convLen = (highLen > lowLen) ? highLen : lowLen;
  uint32_t hi = 0, lo = 0;

  int i, j;
  int minMark = 0, maxMark = 0;

  for (i = 0; i < GraphTraceLen - convLen; ++i) {
    int lowSum = 0, highSum = 0;

    for (j = 0; j < lowLen; ++j) {
      lowSum += LowTone[j]*GraphBuffer[i+j];
    }
    for (j = 0; j < highLen; ++j) {
      highSum += HighTone[j] * GraphBuffer[i + j];
    }
    lowSum = abs(100 * lowSum / lowLen);
    highSum = abs(100 * highSum / highLen);
    GraphBuffer[i] = (highSum << 16) | lowSum;
  }

  for(i = 0; i < GraphTraceLen - convLen - 16; ++i) {
    int lowTot = 0, highTot = 0;
    // 10 and 8 are f_s divided by f_l and f_h, rounded
    for (j = 0; j < 10; ++j) {
      lowTot += (GraphBuffer[i+j] & 0xffff);
    }
    for (j = 0; j < 8; j++) {
      highTot += (GraphBuffer[i + j] >> 16);
    }
    GraphBuffer[i] = lowTot - highTot;
    if (GraphBuffer[i] > maxMark) maxMark = GraphBuffer[i];
    if (GraphBuffer[i] < minMark) minMark = GraphBuffer[i];
  }

  GraphTraceLen -= (convLen + 16);
  RepaintGraphWindow();

  // Find bit-sync (3 lo followed by 3 high) (HID ONLY)
  int max = 0, maxPos = 0;
  for (i = 0; i < 6000; ++i) {
    int dec = 0;
    for (j = 0; j < 3 * lowLen; ++j) {
      dec -= GraphBuffer[i + j];
    }
    for (; j < 3 * (lowLen + highLen ); ++j) {
      dec += GraphBuffer[i + j];
    }
    if (dec > max) {
      max = dec;
      maxPos = i;
    }
  }

  // place start of bit sync marker in graph
  GraphBuffer[maxPos] = maxMark;
  GraphBuffer[maxPos + 1] = minMark;

  maxPos += j;

  // place end of bit sync marker in graph
  GraphBuffer[maxPos] = maxMark;
  GraphBuffer[maxPos+1] = minMark;

  PrintAndLog("actual data bits start at sample %d", maxPos);
  PrintAndLog("length %d/%d", highLen, lowLen);

  uint8_t bits[46] = {0x00};

  // find bit pairs and manchester decode them
  for (i = 0; i < arraylen(bits) - 1; ++i) {
    int dec = 0;
    for (j = 0; j < lowLen; ++j) {
      dec -= GraphBuffer[maxPos + j];
    }
    for (; j < lowLen + highLen; ++j) {
      dec += GraphBuffer[maxPos + j];
    }
    maxPos += j;
    // place inter bit marker in graph
    GraphBuffer[maxPos] = maxMark;
    GraphBuffer[maxPos + 1] = minMark;

    // hi and lo form a 64 bit pair
    hi = (hi << 1) | (lo >> 31);
    lo = (lo << 1);
    // store decoded bit as binary (in hi/lo) and text (in bits[])
    if(dec < 0) {
      bits[i] = '1';
      lo |= 1;
    } else {
      bits[i] = '0';
    }
  }
  PrintAndLog("bits: '%s'", bits);
  PrintAndLog("hex: %08x %08x", hi, lo);
  return 0;
}

int CmdGrid(const char *Cmd)
{
  sscanf(Cmd, "%i %i", &PlotGridX, &PlotGridY);
  PlotGridXdefault= PlotGridX;
  PlotGridYdefault= PlotGridY;
  RepaintGraphWindow();
  return 0;
}

int CmdHexsamples(const char *Cmd)
{
  int i, j;
  int requested = 0;
  int offset = 0;
  char string_buf[25];
  char* string_ptr = string_buf;
  uint8_t got[40000];
 
  sscanf(Cmd, "%i %i", &requested, &offset);

  /* if no args send something */
  if (requested == 0) {
    requested = 8;
  }
  if (offset + requested > sizeof(got)) {
    PrintAndLog("Tried to read past end of buffer, <bytes> + <offset> > 40000");
    return 0;
  } 

  GetFromBigBuf(got,requested,offset);
  WaitForResponse(CMD_ACK,NULL);

  i = 0;
  for (j = 0; j < requested; j++) {
    i++;
    string_ptr += sprintf(string_ptr, "%02x ", got[j]);
    if (i == 8) {
      *(string_ptr - 1) = '\0';    // remove the trailing space
      PrintAndLog("%s", string_buf);
      string_buf[0] = '\0';
      string_ptr = string_buf;
      i = 0;
    }
    if (j == requested - 1 && string_buf[0] != '\0') { // print any remaining bytes
      *(string_ptr - 1) = '\0';
      PrintAndLog("%s", string_buf);
      string_buf[0] = '\0';
    }  
  }
  return 0;
}

int CmdHide(const char *Cmd)
{
  HideGraphWindow();
  return 0;
}

int CmdHpf(const char *Cmd)
{
  int i;
  int accum = 0;

  for (i = 10; i < GraphTraceLen; ++i)
    accum += GraphBuffer[i];
  accum /= (GraphTraceLen - 10);
  for (i = 0; i < GraphTraceLen; ++i)
    GraphBuffer[i] -= accum;

  RepaintGraphWindow();
  return 0;
}

int CmdSamples(const char *Cmd)
{
	uint8_t got[40000] = {0x00};

	int n = strtol(Cmd, NULL, 0);
	if (n == 0) 
		n = 20000;
		
	if (n > sizeof(got)) 
		n = sizeof(got);
  
	PrintAndLog("Reading %d samples from device memory\n", n);
	GetFromBigBuf(got,n,0);
	WaitForResponse(CMD_ACK,NULL);
	for (int j = 0; j < n; ++j) {
		GraphBuffer[j] = ((int)got[j]) - 128;
	}
	GraphTraceLen = n;
	RepaintGraphWindow();
	return 0;
}

int CmdTuneSamples(const char *Cmd)
{
	int timeout = 0;
	printf("\nMeasuring antenna characteristics, please wait...");

	UsbCommand c = {CMD_MEASURE_ANTENNA_TUNING};
	SendCommand(&c);

	UsbCommand resp;
	while(!WaitForResponseTimeout(CMD_MEASURED_ANTENNA_TUNING,&resp,1000)) {
		timeout++;
		printf(".");
		if (timeout > 7) {
			PrintAndLog("\nNo response from Proxmark. Aborting...");
			return 1;
		}
	}

	int peakv, peakf;
	int vLf125, vLf134, vHf;
	vLf125 = resp.arg[0] & 0xffff;
	vLf134 = resp.arg[0] >> 16;
	vHf = resp.arg[1] & 0xffff;;
	peakf = resp.arg[2] & 0xffff;
	peakv = resp.arg[2] >> 16;
	PrintAndLog("");
	PrintAndLog("# LF antenna: %5.2f V @   125.00 kHz", vLf125/1000.0);
	PrintAndLog("# LF antenna: %5.2f V @   134.00 kHz", vLf134/1000.0);
	PrintAndLog("# LF optimal: %5.2f V @%9.2f kHz", peakv/1000.0, 12000.0/(peakf+1));
	PrintAndLog("# HF antenna: %5.2f V @    13.56 MHz", vHf/1000.0);
	if (peakv<2000)
		PrintAndLog("# Your LF antenna is unusable.");
	else if (peakv<10000)
		PrintAndLog("# Your LF antenna is marginal.");
	if (vHf<2000)
		PrintAndLog("# Your HF antenna is unusable.");
	else if (vHf<5000)
		PrintAndLog("# Your HF antenna is marginal.");

	for (int i = 0; i < 256; i++) {
		GraphBuffer[i] = resp.d.asBytes[i] - 128;
	}
  
	PrintAndLog("Done! Divisor 89 is 134khz, 95 is 125khz.\n");
	PrintAndLog("\n");
	GraphTraceLen = 256;
	ShowGraphWindow();

  return 0;
}

int CmdLoad(const char *Cmd)
{
   char filename[FILE_PATH_SIZE] = {0x00};
   int len = 0;

   len = strlen(Cmd);
   if (len > FILE_PATH_SIZE) len = FILE_PATH_SIZE;
   memcpy(filename, Cmd, len);
	
   FILE *f = fopen(filename, "r");
   if (!f) {
     PrintAndLog("couldn't open '%s'", filename);
     return 0;
   }

  GraphTraceLen = 0;
  char line[80];
  while (fgets(line, sizeof (line), f)) {
    GraphBuffer[GraphTraceLen] = atoi(line);
    GraphTraceLen++;
  }
  fclose(f);
  PrintAndLog("loaded %d samples", GraphTraceLen);
  RepaintGraphWindow();
  return 0;
}

int CmdLtrim(const char *Cmd)
{
  int ds = atoi(Cmd);

  for (int i = ds; i < GraphTraceLen; ++i)
    GraphBuffer[i-ds] = GraphBuffer[i];
  GraphTraceLen -= ds;

  RepaintGraphWindow();
  return 0;
}
int CmdRtrim(const char *Cmd)
{
  int ds = atoi(Cmd);

  GraphTraceLen = ds;

  RepaintGraphWindow();
  return 0;
}

/*
 * Manchester demodulate a bitstream. The bitstream needs to be already in
 * the GraphBuffer as 0 and 1 values
 *
 * Give the clock rate as argument in order to help the sync - the algorithm
 * resyncs at each pulse anyway.
 *
 * Not optimized by any means, this is the 1st time I'm writing this type of
 * routine, feel free to improve...
 *
 * 1st argument: clock rate (as number of samples per clock rate)
 *               Typical values can be 64, 32, 128...
 */
int CmdManchesterDemod(const char *Cmd)
{
  int i, j, invert= 0;
  int bit;
  int clock;
  int lastval = 0;
  int low = 0;
  int high = 0;
  int hithigh, hitlow, first;
  int lc = 0;
  int bitidx = 0;
  int bit2idx = 0;
  int warnings = 0;

  /* check if we're inverting output */
  if (*Cmd == 'i')
  {
    PrintAndLog("Inverting output");
    invert = 1;
    ++Cmd;
    do
      ++Cmd;
    while(*Cmd == ' '); // in case a 2nd argument was given
  }

  /* Holds the decoded bitstream: each clock period contains 2 bits       */
  /* later simplified to 1 bit after manchester decoding.                 */
  /* Add 10 bits to allow for noisy / uncertain traces without aborting   */
  /* int BitStream[GraphTraceLen*2/clock+10]; */

  /* But it does not work if compiling on WIndows: therefore we just allocate a */
  /* large array */
  uint8_t BitStream[MAX_GRAPH_TRACE_LEN] = {0x00};

  /* Detect high and lows */
  DetectHighLowInGraph( &high, &low, TRUE);
  
  /* Get our clock */
  clock = GetClock(Cmd, 0); 
  int tolerance = clock/4;

  /* Detect first transition */
  /* Lo-Hi (arbitrary)       */
  /* skip to the first high */
  for (i= 0; i < GraphTraceLen; i++)
    if (GraphBuffer[i] == high)
      break;
  /* now look for the first low */
  for (; i < GraphTraceLen; i++)
  {
    if (GraphBuffer[i] == low)
    {
      lastval = i;
      break;
    }
  }
  
  /* If we're not working with 1/0s, demod based off clock */
  if (high != 1)
  {
    bit = 0; /* We assume the 1st bit is zero, it may not be
              * the case: this routine (I think) has an init problem.
              * Ed.
			  */
    for (; i < (int)(GraphTraceLen / clock); i++)
    {
      hithigh = 0;
      hitlow = 0;
      first = 1;

      /* Find out if we hit both high and low peaks */
      for (j = 0; j < clock; j++)
      {
        if (GraphBuffer[(i * clock) + j] == high)
          hithigh = 1;
        else if (GraphBuffer[(i * clock) + j] == low)
          hitlow = 1;

        /* it doesn't count if it's the first part of our read
           because it's really just trailing from the last sequence */
        if (first && (hithigh || hitlow))
          hithigh = hitlow = 0;
        else
          first = 0;

        if (hithigh && hitlow)
          break;
      }

      /* If we didn't hit both high and low peaks, we had a bit transition */
      if (!hithigh || !hitlow)
        bit ^= 1;

      BitStream[bit2idx++] = bit ^ invert;
    }
  }

  /* standard 1/0 bitstream */
  else
  {

    /* Then detect duration between 2 successive transitions */
    for (bitidx = 1; i < GraphTraceLen; i++)
    {
      if (GraphBuffer[i-1] != GraphBuffer[i])
      {
      lc = i-lastval;
      lastval = i;

      // Error check: if bitidx becomes too large, we do not
      // have a Manchester encoded bitstream or the clock is really
      // wrong!
      if (bitidx > (GraphTraceLen*2/clock+8) ) {
        PrintAndLog("Error: the clock you gave is probably wrong, aborting.");
        return 0;
      }
      // Then switch depending on lc length:
      // Tolerance is 1/4 of clock rate (arbitrary)
      if (abs(lc-clock/2) < tolerance) {
        // Short pulse : either "1" or "0"
        BitStream[bitidx++]=GraphBuffer[i-1];
      } else if (abs(lc-clock) < tolerance) {
        // Long pulse: either "11" or "00"
        BitStream[bitidx++]=GraphBuffer[i-1];
        BitStream[bitidx++]=GraphBuffer[i-1];
      } else {
        // Error
          warnings++;
        PrintAndLog("Warning: Manchester decode error for pulse width detection.");
        PrintAndLog("(too many of those messages mean either the stream is not Manchester encoded, or clock is wrong)");

          if (warnings > 10)
          {
            PrintAndLog("Error: too many detection errors, aborting.");
            return 0;
          }
        }
      }
    }

    // At this stage, we now have a bitstream of "01" ("1") or "10" ("0"), parse it into final decoded bitstream
    // Actually, we overwrite BitStream with the new decoded bitstream, we just need to be careful
    // to stop output at the final bitidx2 value, not bitidx
	
	//http://www.proxmark.org/forum/viewtopic.php?id=403
    for (i = 1; i < bitidx; i += 2) {
      if ((BitStream[i] == 0) && (BitStream[i+1] == 1)) {
        BitStream[bit2idx++] = 1 ^ invert;
    } else if ((BitStream[i] == 1) && (BitStream[i+1] == 0)) {
      BitStream[bit2idx++] = 0 ^ invert;
    } else {
      // We cannot end up in this state, this means we are unsynchronized,
      // move up 1 bit:
      i++;
      warnings++;
      PrintAndLog("Unsynchronized, resync...");
      PrintAndLog("(too many of those messages mean the stream is not Manchester encoded)");

        if (warnings > 10)
        {
          PrintAndLog("Error: too many decode errors, aborting.");
          return 0;
        }
      }
    }
  }

  PrintAndLog("Manchester decoded bitstream");
  // Now output the bitstream to the scrollback by line of 16 bits
  for (i = 0; i < (bit2idx-16); i+=16) {
    PrintAndLog("%i %i %i %i %i %i %i %i %i %i %i %i %i %i %i %i",
      BitStream[i],
      BitStream[i+1],
      BitStream[i+2],
      BitStream[i+3],
      BitStream[i+4],
      BitStream[i+5],
      BitStream[i+6],
      BitStream[i+7],
      BitStream[i+8],
      BitStream[i+9],
      BitStream[i+10],
      BitStream[i+11],
      BitStream[i+12],
      BitStream[i+13],
      BitStream[i+14],
      BitStream[i+15]);
  }
  return bit2idx;
}

/* Modulate our data into manchester */
int CmdManchesterMod(const char *Cmd)
{
  int i, j;
  int bit, lastbit, wave;
  int clock = GetClock(Cmd, 0);
 
  int half = (int)(clock/2);
  
  wave = 0;
  lastbit = 1;
  for (i = 0; i < (int)(GraphTraceLen / clock); i++)
  {
    bit = GraphBuffer[i * clock] ^ 1;

    for (j = 0; j < half; ++j)
      GraphBuffer[(i * clock) + j] = bit ^ lastbit ^ wave;
    for (j = half; j < clock; ++j)
      GraphBuffer[(i * clock) + j] = bit ^ lastbit ^ wave ^ 1;

    /* Keep track of how we start our wave and if we changed or not this time */
    wave ^= bit ^ lastbit;
    lastbit = bit;
  }

  RepaintGraphWindow();
  return 0;
}

int CmdNorm(const char *Cmd)
{
  int i;
  int max = INT_MIN, min = INT_MAX;

  for (i = 10; i < GraphTraceLen; ++i) {
    if (GraphBuffer[i] > max)
      max = GraphBuffer[i];
    if (GraphBuffer[i] < min)
      min = GraphBuffer[i];
  }

  if (max != min) {
    for (i = 0; i < GraphTraceLen; ++i) {
      GraphBuffer[i] = (GraphBuffer[i] - ((max + min) / 2)) * 1000 /
        (max - min);
    }
  }
  RepaintGraphWindow();
  return 0;
}

int CmdPlot(const char *Cmd)
{
  ShowGraphWindow();
  return 0;
}

int CmdSave(const char *Cmd)
{
   char filename[FILE_PATH_SIZE] = {0x00};
   int len = 0;

   len = strlen(Cmd);
   if (len > FILE_PATH_SIZE) len = FILE_PATH_SIZE;
   memcpy(filename, Cmd, len);
   

  FILE *f = fopen(filename, "w");
  if(!f) {
    PrintAndLog("couldn't open '%s'", filename);
    return 0;
  }
  int i;
  for (i = 0; i < GraphTraceLen; i++) {
    fprintf(f, "%d\n", GraphBuffer[i]);
  }
  fclose(f);
  PrintAndLog("saved to '%s'", Cmd);
  return 0;
}

int CmdScale(const char *Cmd)
{
  CursorScaleFactor = atoi(Cmd);
  if (CursorScaleFactor == 0) {
    PrintAndLog("bad, can't have zero scale");
    CursorScaleFactor = 1;
  }
  RepaintGraphWindow();
  return 0;
}

int CmdThreshold(const char *Cmd)
{
  int threshold = atoi(Cmd);

  for (int i = 0; i < GraphTraceLen; ++i) {
    if (GraphBuffer[i] >= threshold)
      GraphBuffer[i] = 1;
    else
      GraphBuffer[i] = -1;
  }
  RepaintGraphWindow();
  return 0;
}

int CmdDirectionalThreshold(const char *Cmd)
{
	int8_t upThres = param_get8(Cmd, 0);
	int8_t downThres = param_get8(Cmd, 1);
  
  printf("Applying Up Threshold: %d, Down Threshold: %d\n", upThres, downThres);
  
  int lastValue = GraphBuffer[0];
  GraphBuffer[0] = 0; // Will be changed at the end, but init 0 as we adjust to last samples value if no threshold kicks in.
  
  for (int i = 1; i < GraphTraceLen; ++i) {
    // Apply first threshold to samples heading up
    if (GraphBuffer[i] >= upThres && GraphBuffer[i] > lastValue)
    {
      lastValue = GraphBuffer[i]; // Buffer last value as we overwrite it.
      GraphBuffer[i] = 1;
    }
    // Apply second threshold to samples heading down
    else if (GraphBuffer[i] <= downThres && GraphBuffer[i] < lastValue)
    {
      lastValue = GraphBuffer[i]; // Buffer last value as we overwrite it.
      GraphBuffer[i] = -1;
    }
    else
    {
      lastValue = GraphBuffer[i]; // Buffer last value as we overwrite it.
      GraphBuffer[i] = GraphBuffer[i-1];

    }
  }
  GraphBuffer[0] = GraphBuffer[1]; // Aline with first edited sample.
  RepaintGraphWindow();
  return 0;
}

int CmdZerocrossings(const char *Cmd)
{
  // Zero-crossings aren't meaningful unless the signal is zero-mean.
  CmdHpf("");

  int sign = 1;
  int zc = 0;
  int lastZc = 0;

  for (int i = 0; i < GraphTraceLen; ++i) {
    if (GraphBuffer[i] * sign >= 0) {
      // No change in sign, reproduce the previous sample count.
      zc++;
      GraphBuffer[i] = lastZc;
    } else {
      // Change in sign, reset the sample count.
      sign = -sign;
      GraphBuffer[i] = lastZc;
      if (sign > 0) {
        lastZc = zc;
        zc = 0;
      }
    }
  }

  RepaintGraphWindow();
  return 0;
}

static command_t CommandTable[] = 
{
  {"help",          CmdHelp,            1, "This help"},
  {"amp",           CmdAmp,             1, "Amplify peaks"},
  {"askdemod",      Cmdaskdemod,        1, "<0 or 1> -- Attempt to demodulate simple ASK tags"},
  {"askmandemod",   Cmdaskmandemod,     1, "[clock] [invert <0|1>] -- Attempt to demodulate ASK/Manchester tags and output binary"},
  {"askrawdemod",   Cmdaskrawdemod,     1, "[clock] [invert <0|1>] -- Attempt to demodulate ASK tags and output binary"},
  {"autocorr",      CmdAutoCorr,        1, "<window length> -- Autocorrelation over window"},
  {"biphaserawdecode",CmdBiphaseDecodeRaw,1,"[offset] Biphase decode binary stream already in graph buffer (offset = bit to start decode from)"},
  {"bitsamples",    CmdBitsamples,      0, "Get raw samples as bitstring"},
  {"bitstream",     CmdBitstream,       1, "[clock rate] -- Convert waveform into a bitstream"},
  {"buffclear",     CmdBuffClear,       1, "Clear sample buffer and graph window"},
  {"dec",           CmdDec,             1, "Decimate samples"},
  {"detectaskclock",CmdDetectClockRate, 1, "Detect ASK clock rate"},
  {"dirthreshold",  CmdDirectionalThreshold,   1, "<thres up> <thres down> -- Max rising higher up-thres/ Min falling lower down-thres, keep rest as prev."},
  {"em4xdecode",    CmdEm410xDecode,    1, "decode em4x from graph buffer"},
  {"fskdemod",      CmdFSKdemod,        1, "Demodulate graph window as a HID FSK"},
  {"fskhiddemod",   CmdFSKdemodHID,     1, "Demodulate graph window as a HID FSK using raw"},
  {"fskiodemod",    CmdFSKdemodIO,      1, "Demodulate graph window as an IO Prox FSK using raw"},
  {"fskrawdemod",   CmdFSKrawdemod,     1, "[clock rate] [invert] [rchigh] [rclow] Demodulate graph window from FSK to binary (clock = 50)(invert = 1 or 0)(rchigh = 10)(rclow=8)"},
  {"grid",          CmdGrid,            1, "<x> <y> -- overlay grid on graph window, use zero value to turn off either"},
  {"hexsamples",    CmdHexsamples,      0, "<bytes> [<offset>] -- Dump big buffer as hex bytes"},  
  {"hide",          CmdHide,            1, "Hide graph window"},
  {"hpf",           CmdHpf,             1, "Remove DC offset from trace"},
  {"load",          CmdLoad,            1, "<filename> -- Load trace (to graph window"},
  {"ltrim",         CmdLtrim,           1, "<samples> -- Trim samples from left of trace"},
  {"rtrim",         CmdRtrim,           1, "<location to end trace> -- Trim samples from right of trace"},
  {"mandemod",      CmdManchesterDemod, 1, "[i] [clock rate] -- Manchester demodulate binary stream (option 'i' to invert output)"},
  {"manrawdecode",  Cmdmandecoderaw,    1, "Manchester decode binary stream already in graph buffer"},
  {"manmod",        CmdManchesterMod,   1, "[clock rate] -- Manchester modulate a binary stream"},
  {"norm",          CmdNorm,            1, "Normalize max/min to +/-500"},
  {"plot",          CmdPlot,            1, "Show graph window (hit 'h' in window for keystroke help)"},
  {"samples",       CmdSamples,         0, "[512 - 40000] -- Get raw samples for graph window"},
  {"save",          CmdSave,            1, "<filename> -- Save trace (from graph window)"},
  {"scale",         CmdScale,           1, "<int> -- Set cursor display scale"},
  {"threshold",     CmdThreshold,       1, "<threshold> -- Maximize/minimize every value in the graph window depending on threshold"},
  {"tune",          CmdTuneSamples,     0, "Get hw tune samples for graph window"},
  {"zerocrossings", CmdZerocrossings,   1, "Count time between zero-crossings"},
  {NULL, NULL, 0, NULL}
};

int CmdData(const char *Cmd)
{
  CmdsParse(CommandTable, Cmd);
  return 0;
}

int CmdHelp(const char *Cmd)
{
  CmdsHelp(CommandTable);
  return 0;
}